Thermochromic Shifts of Absorption and Fluorescence Spectra and Excited State Dipole Moment of PRODAN

2000 ◽  
Vol 55 (5) ◽  
pp. 550-554 ◽  
Author(s):  
A. Kawski ◽  
B. Kukliński ◽  
P. Bojarski
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Ethyl Acetate ◽  
Satisfactory Agreement ◽  
Fluorescence Spectra ◽  
Dipole Moments ◽  
Absorption And Fluorescence Spectra ◽  
Shift Method ◽  
Solvatochromic Method ◽  
Excited State Dipole Moment

Abstract Using the thermochromic shift method of absorption and fluorescence spectra, the dipole moments in the ground, µg, and excited. µe , state are simultaneously determined for PRODAN in ethyl acetate. The obtained values for µg and µe are compared with those previously determined by the solvatochromic method for two different Onsager radii, and a satisfactory agreement has been obtained

scholarly journals Solvatochromic Study of Supramolecular Amphiphile Based on Calix[4]arene Connected to a Fluorescent Benzofurazan Moiety at Lower Rim: Evaluation of Ground and Excited State Dipole Moments-=SUP=-*-=/SUP=-

2020 ◽  
Vol 128 (12) ◽  
pp. 1864
Author(s):  
S. Joshi
Keyword(s):  
Dipole Moment ◽  
Excited State ◽  
Ground State ◽  
Fluorescence Spectra ◽  
Dipole Moments ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Fluorescence Emission ◽  
Wide Range ◽  
Excited State Dipole Moment

Photophysical properties of a supramolecular amphiphile of calix[4]arene having benzofurazan moiety at the lower rim, L has been studied. Electronic absorption and fluorescence spectra of L have been recorded in wide range of solvents of different polarities and data were used to study solvatochromic properties. The ground state and the excited state dipole moment of L were estimated from the Bakhshiev's and Bilot-Kawaski's equations. High value of dipole moment is observed for excited state as compared to ground state value and this is attributed to more polar excited state of molecule. Also, fluorescence emission peak undergoes a bathochromic shift with increase in the polarity of the solvent, confirming π-> π* transition. Scanning electron microscopy reveals that the aggregation of L is increased on going from the polar to non polar solvents. Keywords: solvatochromism, benzofurazan, dipole moment, quantum yield, absorption, fluoresence.

Theoretical and Experimental Investigation on Dipole Moment of Synthetized yt-Base in the Ground and Excited States

1979 ◽  
Vol 34 (2) ◽  
pp. 172-175 ◽  
Author(s):  
I. Gryczyński ◽  
Ch. Jung ◽  
A. Kawski ◽  
S. Paszyc ◽  
B. Skalski
Keyword(s):  
Experimental Investigation ◽  
Dipole Moment ◽  
Excited State ◽  
Excited States ◽  
Ground State ◽  
Fluorescence Spectra ◽  
Dipole Moments ◽  
Aprotic Solvents ◽  
Absorption And Fluorescence Spectra ◽  
First Excited State

Abstract The electric dipole moment of yt-Base calculated by the CNDO/S and JNDO/S method is μg = 3.42 D and μg = 3.74 D in the ground state and μe = 4.41 D and μe = 5.67 D in the first excited ππ*-state, respectively, μg and μe being nearly antiparallel. Measurements of absorption and fluorescence spectra of yt-Base in aprotic solvents of different polarity yielded μg = 3.8 D and μe = 4.3 D and the directions of dipole moments were found to be nearly antiparallel.This comparison may be considered as an indication for the ππ* character of the observable first excited state, although the CNDO/S-and JNDO/S-calculations predict a nπ*-state as the lowest lying excited state

Thermochromic Excited – State Dipole Moment Measurements of p-Cyano-N,N-diethylaniline in Ethyl Acetate

2003 ◽  
Vol 58 (2-3) ◽  
pp. 118-120
Author(s):  
A. Kawski ◽  
B. Kuklinski ◽  
P. Bojarski
Keyword(s):  
Ethyl Acetate ◽  
Fluorescence Spectra ◽  
Dipole Moments ◽  
Effect Of Temperature ◽  
Absorption And Fluorescence Spectra ◽  
Lower Intensity ◽  
Electric Dipole Moments ◽  
Long Wavelength ◽  
Wavelength Emission ◽  
Excited State Dipole Moment

The effect of temperature on absorption and fluorescence spectra of p-cyano-N,N-diethylaniline (CDEA) in ethyl acetate has been studied for temperatures ranging from 293 K to 418 K. At T = 293 K two fluorescence bands are observed: long wavelength emission (LE) and short wavelength emission (SE) of much lower intensity compared to the first one.With temperature increase (which leads to the decrease of dielectric constant ε of the solvent) the intensity of SE band strongly increases, however its hypsochromic shift compared to the shift of LE band is rather slight. The electric dipole moments for CDEA determined based on this thermochromic method are: μLEe = 13.4 D and μSEe = 7.5 D for μg = 5.5 D, and μLE e = 13.9 D and μSEe = 8.3 D for μg = 6.6 D. The values obtained are compared with those of p-cyano-N,N-dimethylaniline (CDMA) determined using different methods.

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